Database Autonomy Service:Scheduled auto scaling

Usage notes

• To scale up a database instance on a regular basis, you must configure a scheduled auto scaling policy for the database instance.

• All time-related parameters are displayed in UTC+8. If this time zone is not supported in your region, you must convert the time before you configure the parameters.

• You can apply only one auto scaling policy of each mode to a database instance.

• Retry intervals are not supported for scheduled auto scaling policies. If a scheduled auto scaling policy fails to be executed, the system does not retry to execute the policy.

• If the Duration or Scale-back Time parameter is modified after an instance is scaled up, the instance is scaled back to the previous specifications based on the new time specified by either of the two parameters.

• In the following scenarios, the database instance may not be scaled back to its previous specifications even if the Duration or Scale-back Time parameter is specified:

  • The specifications of the database instance are manually or automatically changed again after the scheduled auto scaling policy is executed. If the instance specifications are different from those specified in the policy, the database instance is not scaled back.

  • One or more metrics of the database instance do not meet specific standards. For example, the memory of an instance is scaled up from 1 GB to 4 GB based on a scheduled auto scaling policy. If 1 GB of memory has been used before the instance is scaled back, the scale-back operation is not performed because the memory usage increases to 100% during the operation. This ensures the stability and security of your business.

  • The instance is in a state in which specification changes are not allowed, such as the Changing Specifications or Migrating state.

Examples

DAS performs scaling operations on your instances once or on a regular basis. DAS may scale your instances every day, week, or month. For example, if the peak hours of your business start at 2:00 on the first day of every month and end at 2:00 on the third day of every month, you can use the scheduled auto scaling feature to scale up your instances during peak hours and scale the instances back during off-peak hours.

Overview

Create a scheduled auto scaling policy

1. Log on to the DAS console.

2. Create a scheduled auto scaling policy.

   • Create a scheduled auto scaling policy on the Management and Settings page.

     1. In the left-side navigation pane, click Management and Settings.

     2. On the Auto Scaling Policies page, click Add Policy. In the Add Policy panel, configure parameters for the scheduled auto scaling policy.

        Table 1. Parameters

        Parameter	Description
        Policy Name	The name of the policy.
        Mode	The mode of the policy. Select Scheduled Auto Scaling.
        Engine Type	The type of the database engine.
        Specifications	The specifications of the selected database engine.
        Operation	The operations to be performed. For ApsaraDB RDS for MySQL instances and ApsaraDB for Redis instances, only Adjust Instance Specifications is supported. For PolarDB for MySQL clusters, Adjust Instance Specifications and Increase Number of Read-only Nodes are supported.
        Valid From	The time range during which the policy is effective. Start time is a required parameter. You must set this parameter to a date later than the current date. End time is an optional parameter. If you set the Recurrence parameter to N/A(Execute Only Once), the scheduled auto scaling policy is executed only once and is not subject to the End time parameter. If you set the Recurrence parameter to Daily, Weekly, or Monthly and leave the End time parameter empty, the scheduled auto scaling policy is repeatedly executed based on the specified cycle. If you specify an end time, the system stops executing the policy after the end time.
        Recurrence	The interval at which the scaling operation is performed. Valid values: N/A(Execute Only Once) Scaling Start Time: You must configure this parameter. Duration: You can configure this parameter or leave this parameter empty. Set this parameter to a positive integer. Unit: hours. If you leave this parameter empty, the instance is not scaled back after the auto scaling policy is executed. If you configure this parameter, the instance is scaled back to its original specifications after the auto scaling policy is executed. Daily: Scaling Start Time: You must configure this parameter. Scale-back Time: You must configure this parameter. If the scaling start time is earlier than the scale-back time, the two points in time of a single execution of the policy are within the same day. If the scaling start time is later than the scale-back time, the two points in time of a single execution of the policy are not within the same day. The instance is scaled back one day after the scaling starts. Note The time specified by the Scale-back Time parameter must be at least 1 hour later than that specified by the Scaling Start Time parameter. The scaling start time must be at least 1 hour later than the scale-back time of the previous execution of the policy. If you specify an end time and the end time is set to a date between the scaling start time and scale-back time of the last execution of the policy, the last execution of the policy is not performed. Weekly: Scaling Start Time: You must configure this parameter. Scale-back Time: You must configure this parameter. If the scaling start time is earlier than the scale-back time, the two points in time of a single execution of the policy are within the same week. If the scaling start time is later than the scale-back time, the two points in time of a single execution of the policy are not within the same week. The instance is scaled back within the subsequent week after the scaling starts. Note The time specified by the Scale-back Time parameter must be at least 1 hour later than that specified by the Scaling Start Time parameter. The scaling start time must be at least 1 hour later than the scale-back time of the previous execution of the policy. If the end time is set to a date between the scaling start time and scale-back time of the last execution of the policy, the last execution of the policy is not performed. Monthly Scaling Start Time: You must configure this parameter. Scale-back Time: You must configure this parameter. If the scaling start time is earlier than the scale-back time, the two points in time of a single execution of the policy are within the same month. If the scaling start time is later than the scale-back time, the two points in time of a single execution of the policy are not within the same month. The instance is scaled back within the subsequent month after the scaling starts. Note The time specified by the Scale-back Time parameter must be at least 1 hour later than that specified by the Scaling Start Time parameter. The scaling start time must be at least 1 hour later than the scale-back time of the previous execution of the policy. If the end time is set to a date between the scaling start time and scale-back time of the last execution of the policy, the last execution of the policy is not performed.

     3. In the Auto Scaling Policies section, find the policy that you created and click Apply in the Actions column.

     4. In the Apply Policies dialog box, select the database instances to which you want to apply the policy, and click the icon.

     5. Click Confirm to apply the policy to the selected database instances.

   • Create a scheduled auto scaling policy on the Autonomous Function Settings tab of the Autonomous Function Management panel.

     1. In the left-side navigation pane, click Instance Monitoring.

     2. On the page that appears, find the database instance to which you want to apply a scheduled auto scaling policy and click the instance ID. The instance details page appears.

     3. Click Autonomy Service Settings in the upper-right corner.

     4. On the Autonomous Function Settings tab of the Autonomous Function Management panel, click the Auto Scaling tab. In the Applied Policies section, click Add Policy to create a scheduled scaling policy. For more information, see the Table 1. Parameters section of this topic.

     5. In the Recommended Policies section, find the policy that you created and click Apply in the Actions column.

        Note

        • To modify a policy, click Modify in the Actions column. In the Update Policy panel, modify the policy settings.

        • If you no longer want to apply a policy to your RDS instance, click Cancel in the Actions column of the policy in the Applied Policy section.

     6. Click OK.

View the results of scheduled auto scaling

1. In the left-side navigation pane of the DAS console, click Instance Monitoring.

2. On the page that appears, find the database instance for which scheduled auto scaling is enabled and click the instance ID. The instance details page appears.

3. In the left-side navigation pane, click Autonomy Center.

4. On the Autonomy Center page, select a time range to view the auto scaling events that occurred during the selected time range.

5. Click Details in the Auto-Scaling Events section to view the details of scheduled auto scaling events.

   

FAQ

Q: What do I do if the specifications of the instance have reached the upper limit?

References

For information about how to change the specifications of your instances, see the following topics:

• ApsaraDB RDS for MySQL: Change instance specifications

• PolarDB for MySQL: Manually upgrade or downgrade a PolarDB cluster

• ApsaraDB for Redis: Change the configurations of an instance